Correlation of nitrites in breath condensates and lung function in asthmatic children

Abstract

We aimed to evaluate the value of exhaled breath condensates in monitoring airway inflammation in childhood asthma before and after high altitude climate therapy. Forty-eight asthmatic children on regular anti-asthma treatment with a normal FEV1 and positive skin prick test for house dust mites were recruited. All children had been referred to an alpine clinic for high altitude climate therapy, because of persistent asthmatic symptoms despite use of daily anti-inflammatory treatment. Subjects were assessed on their arrival and before departure from the alpine clinic. Spirometry, bronchial provocation tests and measurements of nitrites in breath condensates were performed. Median levels of nitrites were significantly higher before than after high altitude climate therapy (1.27 vs. 0.93 microm; p = 0.008). In addition, MEF50 improved significantly (p < 0.0005). There was a significant correlation between nitrites in breath condensates and MEF50 (r = -0.63, p < 0.0001), symptoms (r = 0.47, p = 0.0007) and airway hyper-reactivity (AHR) (r = -0.41, p = 0.004). In summary, we found a reduction in nitrites in breath condensates after a high altitude climate therapy. Significant correlations were found between nitrites and MEF50, AHR and symptoms. We conclude that the measurement of nitrites may be feasible to objectively assess airway inflammation in asthmatic children in order to detect ongoing inflammation in children with normal FEV1 but persistent symptoms.